Non-volatile data storage devices, such as universal serial bus (USB) flash memory devices or removable storage cards, have allowed for increased portability of data and software applications. Flash memory devices can enhance data storage density by storing multiple bits in each flash memory cell. For example, Multi-Level Cell (MLC) flash memory devices provide increased storage density by storing 3 bits per cell, 4 bits per cell, or more. Although increasing the number of bits per cell and reducing device feature dimensions may increase a storage density of a memory device, a bit error rate of data stored at the memory device may also increase.
Error correction coding (ECC) is often used to correct errors that occur in data read from a memory device. Prior to storage, data may be encoded by an ECC encoder to generate redundant information (e.g., “parity bits”) that may be stored with the data as an ECC codeword. As more parity bits are used, an error correction capacity of the ECC increases and a number of bits required to store the encoded data also increases.
In order to take advantage of increased error correction capability due to increased codeword length, ECC codewords may be formed that span multiple logical pages of a MLC flash memory. However, storage of multiple pages of data in a controller of a data storage device for encoding into a multi-page codeword may require additional complexity and memory (e.g., random access memory (RAM)) at the controller (and therefore increased cost of manufacture), increased write latency, and/or increased risk of data loss in the event of power loss at the controller before the multi-page codeword can be transferred to non-volatile memory.